Explain trigger, Database Management System

Assignment Help:

What is Trigger?

A trigger is a SQL procedure that initiates an action when an event (INSERT, DELETE or UPDATE) occurs. Triggers are kept in and managed by the DBMS. Triggers are used to maintain the referential integrity of data by changing the data in a systematic fashion. A trigger cannot be called or implemented; DBMS automatically fires the trigger as a result of a data modification to the associated table. Triggers can be viewed as same to stored procedures in that both having of procedural logic that is kept at the database level. Stored procedures, though, are not event-drive and are not attached to a specific table as triggers are. Stored procedures are explicitly implemented by invoking a CALL to the procedure whereas triggers are implicitly executed. In addition, triggers can also execute stored procedures.

 


Related Discussions:- Explain trigger

Relationship cardinality, Cardinality shows the number of instances of an e...

Cardinality shows the number of instances of an entity associated with another entity participating in a relationship. Depend on the cardinality binary relationship can be further

How to apply the bcnf decomposition , Consider the following relational sch...

Consider the following relational scheme: R (a,b,c,d,e,f) and its corresponding set of FDs {d→ a, be → c, ac → e, b → f, f → d, a → c}. a. Is the following decomposition i) non

What is secondary index, What is Secondary Index While making the index...

What is Secondary Index While making the index, generally the index table is kept in the primary memory (RAM) and the main table, because of its size is keeps in the secondary

What features relational dbms contribute level of integrity, A well-maintai...

A well-maintained relational DBMS has a high level of data integrity. What features of a relational DBMS contribute towards this level of integrity? Relational DBMS gives high

Original Database, I need an ERD created for any original database(can be o...

I need an ERD created for any original database(can be on anything). It needs to be 3NF. I then need all the CREATE STATEMENTS, INSERT STATEMENTS(anything you can think of as long

Create table and insert data manufacturer-dbms, Create a table according to...

Create a table according to given data:  AmbulanceDriver(Driver_Number#, Name, Address, Birth_Date) AmbulanceDriverTeam(Team_Number#, Driver_Number#, Join_Date, Lea

single products ordered, For Colorado customers calculate the number of si...

For Colorado customers calculate the number of single products ordered. If a product is purchased on multiple orders, it should be counted only single time. The result should conta

Which types of data supported by mysql, Which types of data supported by My...

Which types of data supported by MySQL for Time and Date formats?  MySQL supports a number of time and date column formats: Some of them are 1) DATE 2) DATETIME 3) TIM

What are stored and derived attributes, What are stored and derived attribu...

What are stored and derived attributes? Stored attributes: The attributes keeps in a data base are known as stored attributes. Derived attributes: The attributes that are de

What is class diagram, Class Diagram A class diagram is required to su...

Class Diagram A class diagram is required to support functional necessity of system. In a static design view, class diagram is used to model vocabulary of the system, simple c

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd